Estimates show that trees and shrubs lining the South Platte Basin’s rivers and irrigation ditches — salt cedars, Russian olives, cottonwoods and others — collectively consume hundreds of thousands of acre feet of water each year, although comprehensive studies on the issue in the South Platte Basin are few, and also outdated, some say.

Some experts believe the amount of water consumed by those plants — called phreatophytes — could be rivaling or even surpassing the more than 600,000 acre feet of water that, according to Colorado Department of Natural Resources, were delivered to all of the South Platte Basin’s municipalities in 2010.

And in a year like 2012 — one in which rainfall is at a record-low, some farmers’ irrigation ditches are running dry, and cities are having to watch their supplies closely — many agree some of that water could be going to a more beneficial use than quenching the thirst of vegetation along banks in the South Platte Basin, some of which isn’t native to the area in the first place…

Additionally, some question how much water users would actually benefit in the long run if that vegetation was eradicated. Water officials and environmentalists agree that some kind of vegetation would be needed in place of the removed plants, since root systems are necessary for keeping the river’s banks from eroding, and vegetation would also be needed to provide habitats for wildlife in those areas.

It’s also not clear who would legally be entitled to the water that’s salvaged through eradicating phreatophytes. In recent decades, the state’s water courts have denied requests from individuals wanting to clear their property of trees and shrubs and stake claim to the water that’s saved…

“This issue is certainly on a lot of peoples’ radars right now … but there’s still a lot we don’t know,” said Harold Evans, chairman of the city of Greeley Water and Sewer Board, who also serves on the South Platte Roundtable. “I think we’re all in favor of finding ways to make water more available to users. We just need to learn more about this and see what’s feasible.”[…]

In recent years, the South Platte Roundtable — made up of water officials and experts in the region who convene to discuss ways of solving the water-supply gap — has spearheaded efforts to attain about $250,000 to eradicate the Russian olives and salt cedars along the South Platte River near Brush.

More invasive species coverage here. More tamarisk control coverage here and here.